In photofinishing, customer images are printed onto a photographic paper. Conventionally this printing has been optical, using a light source which has passed through a negative to be printed to expose the paper. More recently, it has been suggested that the exposure can be from a digitally captured image, using a CRT, laser or light emitting diode printer. At wholesale photofinishing laboratories, where large numbers of images must be printed in a short time, the paper is normally supplied from a web in the form of a roll mounted within a paper dispensing cassette in a known manner. The paper cassette is light tight when closed for transport to and from the printer, and is typically loaded in a dark room to avoid undesirable fogging of the photographic paper. Photographic paper rolls are typically mounted on cardboard cores which in turn are mounted on an intercore dimensioned to fit on a spindle which is driven by the printer. Rotation of the spindle can control dispensing and uptake of a paper roll. Following exposure, the web is chemically developed in a known manner and then cut to yield paper prints of many individual images which are then supplied to respective customers.
During the printing process, it is necessary to correctly advance paper through the printer such that the paper position at the printing gate is precisely controlled. This is true of optical printers to avoid wasting paper by controlling the spacing between successive prints. However, in digital printers where printing may occur one line at a time (such as by a laser), control of paper dispensing and uptake by precisely controlling cassette spindle rotation, can become even more important. Thus, rotational slippage of a paper roll core on the intercore on which it is mounted, or slippage of the intercore on the spindle on which it is mounted, is very undesirable. To position and hold a paper roll within the cassette, the conventional approach has been to provide an intercore with flanges spaced apart on a hollow shaft a distance corresponding to the width of the roll which it is intended to mount. One or more flanges are removable to permit mounting of the roll. A tight frictional fit between the intercore shaft has typically been relied upon to ensure the paper roll is driven by the spindle on which it is mounted. This creates a problem in that paper cassettes are typically loaded in a darkroom. To attempt to fit a paper roll core onto a tightly fitting intercore shaft in such an environment can be a difficult exercise. Furthermore, even when mounted, under high loads frictional engagement between the intercore shaft and the cardboard core is always a possibility.
It would be desirable then to provide some way in which a photographic paper roll can be readily mounted on an intercore in a darkroom environment without trying to force the paper roll core onto a tightly fitting intercore shaft. It would also be desirable if some means were provided for maintaining good engagement between a core and the intercore.